Appliances, such as ovens, often have one or more racks generally within the appliance for the placing of cookware, food, and other items within the oven. Additionally, one or more heating elements are provided for heating and cooking the food or other items located within the oven.
In a conventional oven, the oven cavity temperature is controlled by a temperature regulator that turns the heating element on or off as necessary. In addition or alternatively, some ovens further include a convection heating system that typically includes either a gas-fired combustion chamber separate from the oven cavity, or a resistive heating element energized by an electric current, but may also include other types of heating elements such as, for example, an infrared energy source.
A convection oven heats an object in an oven cavity by transferring heat energy from heating elements to the object by circulation of a gas within the oven cavity. Typically, a thermal sensor senses the temperature of the gas and a regulator controls the operation of the heating elements in response to the sensed temperature to maintain a desired operating temperature in the oven cavity. Although the circulated gas in a convection oven for cooking food is typically air, other gases may be employed such as nitrogen, steam, or combustion gases from gas-fired burners, depending upon the oven application. Thus, although convection ovens are commonly used for cooking and baking food, convection oven applications are not limited to cooking and baking. Convection ovens may also be employed in industrial or commercial applications that do not directly cook food.
It is generally known that using a blower, such as a fan, to promote air circulation can dramatically improve the uniformity of air temperature distribution within the oven cavity of a convection oven. However, unmanaged air flow can still be uneven, leading to undesirable cooking or drying of foods.